He-Pin(kerr)

@johanandren Should update the document of `statefulMapConcat` of the `state` may be lost when the stream completes, suggests using `statefulMap` and `mapConcat` instead?

It will help https://github.com/akka/akka/issues/24951 too

@patriknw Thanks for the review, I did a quick local try and can't find a way to keep the state safe ```scala def statefulMap[S, T](create: () => S)(f: (S, Out)...

@patriknw @jrudolph ping~~

I rebased on to the current `main`

https://github.com/akka/akka/runs/6046259746?check_suite_focus=true#step:5:33745

https://github.com/akka/akka/actions/runs/3050597628/jobs/4917861326#step:5:34164

Ok, the scala docs say it will retry infinitely，then seems there is no reason to mark it deprecated？

Keep recoverWith as-is and also introduce fallbackTo? _最初由 viktorklang 在 https://github.com/akka/akka/issues/20123#issuecomment-200757981 发布_

I just think it should not be deprecated, it has a good name. and I do expect: ```scala recover 10 recover 10 recover ...